This study determined the effect of single vs. multiple sets of strength training, during the early phase of adaptation, on the strength of different muscle groups in untrained subjects (N = 26). Ss were randomly assigned to one of two groups: 1) elbow flexion single set and knee extension three sets (E1-K3; N = 13), or 2) elbow flexion three sets and knee extension single set (E3-K1; N = 13). Ss trained two days per week for six weeks and each workout consisted of one close chain knee extension exercise and one elbow flexion exercise. Training intensity varied between eight repetition maximum (8 RM) and 12 RM. Unilateral knee extension and elbow flexion strength were tested for both groups at 60°/s on a Biodex System 3 isokinetic dynamometer. Strength was expressed as peak torque.

The increase in peak torque of the knee extensor muscles from week 0 to 6 was significantly higher in the E1-K3 group (10.29%) than in the E3-K1 (3.78%) group. There was no difference in peak torque gains between E1-K3 (7.75%) and E3-K1 (7.44%) for the elbow flexors muscles.

Implication. For untrained individuals, three sets of strength training exercise are preferable for leg exercise while only one set is necessary for arm strength exercise.